Transmitting apparatus.



J. J. COMER.

TRANSMITTING APPARATUS.

Patented Apr. 27, 1915.

2 SHEETS-SHEET lfiVl E/VTO/P:

APPLICATION FILED .IULY16,I9I3.

WITNESSES J J. CO MER.

TRANSMITTING APPARATUS. APPLICATION FILED JULYIG, 1913.

Patented Apr. 27, 1915,

JOHN J. COMER, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ENUNCIATOR COMPANY, OF CHICAGO, ILLINOIS A CORPORATION OF ILLINOIS.

TRANSMITTING APPARATUS.

Specification of Letters Patent.

Patented Apr. 27, 1915.

To all whom it ma concern Be it known t at I, JOHN J. CoMnR, a citizen of the United States of America, and resident of Chicago, Cook county, Ilhnois, have invented a certain new and useful Improvement in Transmitting Apparatus, of which the following is a specificatlon.

My invention relates to improvements in ternately produce compressions and rarefactions in the air, which compressions and rarefactlons afi'ect mlcrophone transmitters,

advantage has been taken of only the com pressions and rarefactions produced on but (no side of the diaphragm, while the corre-' sponding rarefactions and compressions produced simultaneously in the air on the opposite side of the diaphragm have been entirely lost.

One of the objects of my invention is to provide a construction in which the compressicns and rarefactions produced in the air simultaneously on both sides of the diaphragm are both employed to affect microphone transmitters. In this manner the volume of the air vibrations which affect these transmitters is doubled and thus the efficiency and capacity of the apparatus greatly increased.

In the preferred embodiment of my invention, the compressions and rarefactions produced simultaneously on opposite sides of the diaphragm are both employed to operate upon the same microphone transmitter. The compressions roduced upon one side of the diaphragm a cot one side of the diaphragm of the microphone transmitter,

while the rarefactions simultaneously produced on the other side of. the first diaphragm affect the opposite side of the microphone transmitter. In order to increase the capacity of the apparatus, a large number of these microphone transmitters are com= bined into a single multiple unit, the diaphragms of which are simultaneously affected in this manner.

A further embodiment of my invention consists in having the compressions and rarefactions produced on opposite sides of the diaphragm affect separate microphone transmitters, in which manner I am enabled to energize substantially twice the number of transmitters from a single vibrating diaphragm than was heretofore possible when the air vibrations produced on but one side of the diaphragm was employed.

These and other features of my invention will be more clearly understood by having reference to the accompanying drawings, in which I have illustrated certain embodiments of my invention.

Figure l is a plan view partly broken away showing the apparatus embodying the features of my invention. Fig. 2 is a side elevation with a part of the outside casing removed. Fig. 3 is a sectional view showing the construction of the microphone transmitter units. Fig. 4 is a side view of one of the members of the transmitter. Fig. 5 is a plan view partly in section of a modified form of my device. F ig. 6 is a side elevation of the same. Fig. 7 is a sectional View taken on the line 7-7 in Fig. 5.

As shown in Fig. l, I have illustrated a reproducer H of any suitable type, this reproducer consisting essentially of a stylus 2 carried by an arm 3 connected between a pair of diaphragms M. Movement of the stylus traveling over the record 5 vibrates the diaphragms 44, and thus produces alternate compressions and rarefactions in the air located in the tubes 89 connected to the opposite sides of the diaphragms 4-4 by means of the connecting tubes 67. The opposite ends of the tubes 8-9 are connected by front and back walls 1314, which walls form an inclosing casing G for the multiple transmitting unit shown in detail in Fig. 3. This consists essentially of a number of circular members or rings F located adjacent one another but separated a short distance from each other so as to allow sufficient space for the diaphragm 23. These diaphragms are separated from the rings F by means of the rubber washers 22-424, so that a narrow air space is formed on each side of the diaphragms.

The separate units are secured together by means of the through-bolts 15, the various rings F being held in proper position on these bolts by means of the nuts 27. Each i and 9, each member F is partly hollowed out on one side, as indicated at J and shown in dotted lines in F i 4. The adjacent members F are so positionedthat these hollow portions J are on opposite sides of the multiple unitthat is, the hollow portions J of alternate members communicate with the tube 9, while the hollowed portions of the remaining members, which for convenience are designated asKfcommunicate with the air passage 8. 'The opposite walls of the members F, besides these hollow portions, are perforated as shown at L in order to permit the passage of the sound waves therethrough. v I

With this construction it will be seen that the vibrations of the diaphragms 44 set up alternate rarefactions and compressions of the air in the two tubes 8-9. The air compression produced at any instant in the column 9 will pass into the hollow portion J of the ring-F, thence through the opening or perforations L and strike against one side of each of the diaphragms 23, while the rarefaction of the air produced simultaneously in the tube tends to pull on the opposite sides of the diaphragms through the perforations L and the hollow portions K. In this manner I am enabled to operate the diaphragms by the combined effect of the compressions andrarefactions produced in the air passages 89. The effect of the tiple unit.

compression in one passage being augmented by the corresponding rarefaction in the opposite air passage.- These diaphragms 23 then operate on the variable resistance material 21 in the well known manner, to vary the resistance of this material proportionate to the vibrations of the diaphragms 4-4.

In Figs. 5, 6, and 7, I have illustrated a modified form of my invention in which, instead of having the series of sound waves produced on opposite sides of the diaphragms 44, operate upon the same mul- I provide two series of units, one of which is operated by the compressions and rarefactions set up on one side of the diaphragms 44, and the other of which is operated by the corresponding compressions and rarefactions on the other side of said diaphragms. Thus in these figures I have illustrated the reproducer H which vibrates one or more diaphragms in a manner similar to that shown in Figs. 1 and 2 to produce air vibrations in the two air columns 31-32. These air columns are formed by means of the box-shaped members 33. Mounted on opposite sides of these boxshaped members 33 are a series of transmitters 34 which are insulated from the member 33 by means of the washers 35, and are secured thereto by the through-bolts 36. Each of these transmitters can be of any suitable type, but I obtain very efficient results with the transmitter shown, which consists essentially of the diaphragm 37, on the opposite sides of which, and in the central portion of the same, are the granular resistance receptacles 3839. These granular resistance receptacles are carried by the front and back plates 4041, which plates are separated a short distance from the diaphragm 37 by means of suitable washers 42, thereby forming a narrow air space on opposite sides of the marginal sides of the diaphragm. These plates are provided with a series of perforations 3 to permit the passage of sound waves from the interior of the member 33 to the diaphragms.

With this construction, it will be seen that when the reproducer is operated to set up vibrations in the air columns 31-32 that the compressions and rarefactions produced in the column 31 operate one set of transmitters, while the corresponding rarefactions and compressions produced simultaneously in the column 32 operate the second set of transmitters, and in this way I am able to substantially double the capacity of the apparatus, as heretofore when the compres v sions and rarefactions produced on but one side of the diaphragms of the reproducer were employed, the energy set up by the rarefactions and compressions on the opposite side of these diaphragms was lost.

\Vhile I have illustrated and described gest themselves to those skilled in the art.

It is, of course, obvious thatvery good. results could be obtained with other forms of transmitters, although I prefer the construction which I have illustrated. Likewise, instead of having a pair of diaphragms operated by the reproducer H, it is obvious that a single diaphragm could be employed.

What I claim as my invention is:

1. In an apparatus of the class described, a diaphragm, means for vibrating said diaphragm, air columns connected with opposite sides of' said diaphragm, and a microphone transmitter adapted to be operated by the simultaneous compressions and rarefactions produced in said air columns.

2. In an apparatus of the class'described, a diaphragm, means for vibrating said diaphragm, an air column communicating with each side of said diaphragm, a microphone transmitter including a diaphragm, and means whereby the rarefactions and compressions set up in one of said air columns affect one side of said diaphragm, while the compressions and rarefactions set up simultaneously in the other of said air columns affect the opposite side of said diaphragm.

3. In. an apparatus of the class described, a reproducer comprising a diaphragm and means for Vibrating the same, an air column communicating with each side of said diaphragm, and aplurality of microphone transmitters adapted to be operated by the compressions and rarefactions of the air in said air columns.

4. In an apparatus of'the class described,

a reproducer comprising one or more diaphragms and means for vibrating same, an air column communicating with each side of said diaphragms, a multiple transmitter located between said air columns, said transmitter comprising a plurality of diaphragms, means whereby the compressions and rarefactions set up in the air in one of said air columns by the vibrations of said reproducer diaphragms afl'ect one side of each of the diaphragms of said multiple transmitter, and the vibrations set up in the other column of air operate upon the opposite side ofsaid multiple transmitter diaphragms.

5. In an apparatus of the class described, a reproducer comprising one or more dia phragms and means for vibrating same, an air column communicating with each side of said diaphragms, a multiple transmitter located between said air columns, said transmitter comprising a plurality of diaphragms mounted adjacent to each other, resistance material located between each pair of diaphargms, and means for directing the air vibrations produced in one air column into the space between alternate pairs of diaphragms and for directing the air vibrations.

from the other air column into the space between the remaining pairs of diaphragms.

6. In an apparatus of the. class described, a multi le transmitter comprising a plurality 0 rings located adjacent one another but suitably spaced apart, diaphragms located between adjacent rings, resistance material held within said rings and between adjacent diaphragms, and means for simultaneously directing air vibrations against the opposite sides of each of said diaphragms.

7 In an apparatus of the class described,

a multiple transmitter comprising a plurality of rings located adjacent one another but suitably spaced apart, diaphragms located between adjacent rings, resistance inaterial held within said rings and between adjacent diaphragms, and means for directing a series of air compressions and rarefactions against one side of each of said diaphragms, and means for directing simultaneously a series of air rarefactions and compressions against the opposite side of each of said diaphragms.

8. In an apparatus of the class described,

transmitter diaphragms and theair vibra-' tions in the other tube against the opposite sides of said transmitter diaphragms. 9. In an apparatus of the class described, a pair of diaphragms, granular material between said diaphragms, and means for directing sound waves on both sides of said diaphragms. V

10. In an apparatus of the class described, a reproducer comprising a pair of diaphragms, an air column communicating with each side of said pair of diaphragms, and a plurality of microphone transmitters adapted to be simultaneously operated by the compressions and rarefactions of the air in said air columns.

Signed by me at Chicago, Illinois, this eleventh day of July 1913. I

Y .JOHN J. COMER. Witnesses:

E. H. CLEGG, J. NORBY. 

